ABSTRACT
A gutter-shaped structure which is higher anteriorly than posteriorly. This aids rotation of the fetus during the mechanism of labour. The triangular perineal body consisting of the skin, bulbocavernosus, transverse perinei and the pubococcygeus assists with childbirth and defecation. It is these structures which can stretch and tear, or are cut during an episiotomy and require repair during childbirth. False pelvis is known as the bony structures situated above the brim, which have no significance for childbearing. True pelvis is known as the structures found beneath the false pelvis, which form the birth canal. The ring of bones form the brim, cavity and outlet. The sacrococcygeal joint is between the sacrum and coccyx. Sacrotuberous (from the sacrum to the ischial tuberosity) and the sacrospinus (from the ischial spines to the sacrum) ligaments form borders of the obstetric outlet.
